1. Field of the Invention
The present invention relates to a wall assembly which includes a drainage track of the type primarily intended for use in combination with exterior insulation and finish systems (generally referred to in the construction industry as EIFS), the construction of which provides for positive drainage of moisture which may collect between a structure's exterior surface or coating and its weather-resistant barrier.
2. Description of the Prior Art
In today's construction industry, numerous residential structures, and even a significant number of commercial structures such as, for example, apartment buildings, have their exterior surfaces finished with a stucco-type coating applied over a foam insulation board. One such board is, for example, that disclosed in U.S. Pat. No. 4,572,865, and other such boards are well known in the prior art and in the construction industry. Such exterior finishes are generically referred to as Exterior Insulation and Finish Systems, and will be referred to hereinafter as EIFS.
While such EIFS constructions have proved to be quite satisfactory for their relative ease of installation, their insulating properties, and their ability to receive a variety of aesthetically-pleasing finishes, a serious and vexing problem associated with EIFS construction exists. This problem is one of water accumulation behind the exterior wall covering. Such water may be the result of condensation, but is frequently the result of wind-driven water that may enter behind the exterior wall covering at any point where the exterior surface of the coating is penetrated. Such water accumulation may be the result of poor workmanship or design, deterioration of flashing or sealants over time, lesser quality doors or windows, or any other penetration or compromise of the exterior finish.
When such water penetration or condensation occurs, absent effective, reliable means for draining the water from behind the EIFS exterior construction, structural damage to the building may occur.
The construction industry has certainly recognized such problems associated with water penetration behind EIFS exteriors, and other insulated building components such as, for example, windows. For example, U.S. Pat. No. 4,569,872 describes an insulating window panel which includes a bottom frame member for draining condensation. According to the disclosure of that patent, a transparent plastic sheet having a number of vertical channels formed therethrough is disposed in face-to-face relationship with a polyethylene closed cell foam sheet. The purpose of the vertical channels is to permit water to flow downwardly, and the lower frame member is dimensioned and configured to provide a drain opening along the bottom thereof. This drain opening is provided by insuring that the composite panel is mounted in spaced apart relation to the bottom of the frame member.
U.S. Pat. No. 2,264,961 discloses a thermal insulation structure having vertical channels formed on one face thereof to provide a ventilating space for the circulation of air to dry out water which may penetrate the insulating material. However, this patent does not disclose or suggest any means for positively draining water from inside the wall.
According to the disclosure of U.S. Pat. No. 4,570,398, concrete may be sprayed onto the exterior of rigid sheet insulation and wire to form a continuous waterproof outer surface. However, one may reasonably question such a statement, for concrete is typically permeable to water.
Finally, U.S. Pat. No. 5,511,346 discloses a rigid, thermoplastic foam board useful in below-grade residential and commercial insulating and drainage applications. According to the disclosure of this patent, the board includes a plurality of vertical channels formed therein to provide for water drainage and to protect a below-grade-building wall from excessive moisture.
Without in any way questioning the asserted utility of the devices and structures identified above, any practical study of these devices reveals significant shortcomings. Virtually none of the prior art devices actually provide means for positively draining water away from the building structure. While a drain opening is provided in the panel disclosed by U.S. Pat. No. 4,569,872, establishing that drain opening clearly requires care and precision in fitting the lower frame member to the composite panel. While the other devices discussed above provide means for "ventilating" insulating panels, none provide for water drainage from behind the panels. It is, therefore, clear that there remains a great need in the art of building constructions utilizing EIFS exteriors so as to provide for the drainage of penetrating water or condensing moisture from behind the insulation so as to prevent water-related structural damage to the building. Such a device must not only provide for positive water drainage, but also must be of economical manufacture and of relatively simple use and installation so as not to adversely affect building costs.